1. Field of the Invention
This invention relates to a patterning process capable of forming two or more kinds of patterns on a substrate, an electrodeposition original plate used in such a process, and a process for producing an optical recording medium or producing a color filter by the use of such an original plate.
2. Related Background Art
As a method for the production of color filters, the method as disclosed in Japanese Patent Application Laid-open No. 61-279003 is known in the art.
The method will be described with reference to FIGS. 2A to 2F. First, on a transparent substrate 21, a transparent electrode 22 is formed. Then, on the transparent electrode 22, a photoresist layer 23 is formed (FIG. 2A).
Next, the photoresist layer is exposed to light through a mask formed to correspond with a pattern of a first hue (e.g., red), followed by development to bare the transparent electrode (FIG. 2B). Next, on the bared portion of the transparent electrode, a red electrodeposited layer 24 is formed using an electrodepositing solution prepared by dissolving or dispersing a red coloring matter in a resin suitable for electrodeposition (FIG. 2C).
Subsequently, in the same manner, the transparent electrode is bared (FIG. 2D) using a mask formed to correspond with a pattern of a second hue (e.g., green), and then a green electrodeposited layer 25 is formed on the newly bared portion in the manner previously described (FIG. 2E). An electrodeposited layer 26 of a third hue (e.g., blue) is further formed in entirely the same manner. Thus, a color filter is obtained (FIG. 2F).
As an example of the application of this method, a method is known in which, after the electrodeposited layers of the respective hues have been formed, a glass substrate having a transfer layer comprising a coated photocurable adhesive is contact-bonded, to the electrodeposited layers, followed by irradiation with light to cause the electrodeposited layers to transfer to the glass substrate.
This method, which employs a technique of photolithography, has a superior pattern precision compared with other processes for producing color filters, e.g., printing, and also can achieve uniform control of coloring layers according to conditions for electrodeposition. Thus, this method is preferable for producing high quality color filters. When the transfer step described above is used, the substrate on which the electrode has been formed can be reused, making it possible to reduce the cost of producing color filters.
This method, however, requires repeating the steps of preparing mask patterns using insulating photosensitive resins such as photoresists on a conductive layer, in the number corresponding to colors, and forming electrodeposited layers on the bared portion of the conductive layer each time one color filter is produced. In such steps, it is difficult to maintain the positional precision of the patterns of the electrodeposited layers with different hues, and further cost reductions for color filters have been desired.